While Nathan Witthoft was earning his PhD at Massachusetts Institute of Technology, he met a woman with color-grapheme synesthesia, a neurological condition where people see letters and numbers in color. Most color-grapheme synesthetes perceive the alphabet in their own color scheme, with each letter possessing a different hue. When tested on her synesthesia, Witthoft noticed that it had reoccurring colors, as if her alphabet followed a set, repeated pattern. She mentioned that as a child she had a set of colored alphabet magnets and her letters matched the colors of the letters in the set.
Witthoft wrote a paper about her and soon others contacted him, noting that their synesthesia mimicked the colors of the magnets. He recruited 11 synesthetes to visit the lab and take some tests. First, he asked the subjects to participate in a battery of tests to determine whether they were, in fact, synesthetes (the tests come from synesthete.org; anyone can register and take them online). Then, they participated in a timed color-matching test, where they selected the shade that corresponded with their letter.
Read the whole story: NBC